As of late, three-dimensional (3D) objects are being used in various fields of application such as games, digital movies, and computer-aided design (CAD). Such development in technology for rendering a real sensation has enabled the 3D objects to include hundreds or thousands of vertices and areas. However, the 3D mesh for restoring the 3D objects may require a vast storage capacity, a considerable amount of calculation, and a broad transmission bandwidth. Accordingly, there is a need for encoding and compressing the 3D mesh in order to efficiently transmit, store, and render the 3D objects.
The more complicated a form of the 3D objects, the more complicated a form of the 3D mesh. In addition, all information included in the 3D mesh may need to be transmitted to a decoder so as to restore the 3D objects. Such a method is referred to as a single rate coding.
A conventional method of the single rate coding may have a disadvantage in that a waiting time is required until vertex position information and vertex connectivity information are transmitted in full to restore the 3D objects because the information on the position of vertices configuring the 3D mesh and the information on the connectivity of vertices are transmitted sequentially.
Also, a progressive codec method in which a 3D mesh is progressively compressed and transmitted may be suggested. However, a conventional progressive codec method has a lower compression rate than the single rate coding because additional information is included in the progressive codec method.
Accordingly, there is a desire for technology for enhancing a compression rate when a 3D mesh is progressively compressed.